The invention relate, to a method for balancing motor vehicle wheels.
Prior art balancing systems on balancing machines are characterized in that they reach a predetermined velocity to which the wheel has to be brought so that the balancing operation can be carried out.
This operation, as s well known, comprises recording the forces due to imbalance by means of force transducers, applied on the shaft the wheel is mounted on, and the processing of transducer signals with the aim of obtaining an indication of the entity and geometric arrangement of masses to be applied to the wheel to correct such an imbalance. Once the above-mentioned rotation speed has been reached, some known machines stay at that same velocity throughout the time necessary for balancing. This means that the motor driving the shaft on which the wheel is mounted has to be kept in motion.
Other balancers use the motor only during the start-up phase, to accelerate the wheel to the balancing speed, after which the motor is turned off and all the balancing operations are carried out with the system operating by pure inertia, which means in effect that the wheel speed is gradually diminishing.
These prior art machines have limits and drawbacks when on a same machine it is necessary to carry out balancing operations on wheels which are of very different types.
To bring the machine up to the predetermined working speed when a larger wheel is mounted, a longer time is needed than in the case of smaller or lighter wheels.
A further negative characteristic of known balancing machines is having to size the motor according to the largest wheels which will have to be mounted, i.e. those with highest inertia, so that even for these wheels an acceleration can be reached which will be sufficient for the balancing operation within an acceptable operation time.
A further limit of the known machines can be traced to the fact that normally the number of wheel rotations taken into consideration and achieved in the interest of reading off the forces due to imbalance is determined once for all wheels, independently of the inertia characteristics of the wheel to be balanced. For this reason, due to the considerable differences that might emerge during the generation of the imbalance signals (differences originating from wheels of very different types) it might become necessary to adopt signal interpretation devices on the balancing machines, which devices interpret the signals and act upon them (for example, by amplifying small signals produced by very small wheels).